The Relevance of Optical Coherence Tomography Angiography in Screening and Monitoring Hypertensive Patients with...

Background: Our study evaluated the correlation between internal carotid artery stenosis (ICAS) and retinal microvascular changes in patients with hypertensive retinopathy, dyslipidemia and ICAS. We analyzed vascular measurements provided by optical coherence tomography angiography (OCTA) and carotid Doppler ultrasonography (US) and linked OCTA parameters with carotid artery US measurements on the same side. Statistical differences in OCTA analysis among three groups (no stenosis, mild stenosis and moderate stenosis) were evaluated and correlated with carotid Doppler parameters. Our study aimed to evaluate whether OCTA can be proposed as a screening method in patients diagnosed with mild and moderate ICAS in order to improve the early detection of carotid changes, thus potentially reducing the rate of cardiovascular and cerebral complications of ICAS. Methods: We conducted a study on hypertensive patients with ICAS using six OCTA parameters in the analysis of the retinal vasculature and carotid Doppler US velocities of three carotid arteries and the vertebral artery (VA). Kruskal-Wallis and Dunn's post hoc tests were used to determine whether there were statistically significant differences between the normal, mild and moderate stenosis groups. Spearman and Pearson correlation were used to obtain correlations among OCTA parameters such as the foveal avascular zone (FAZ), non-flow area (NFA), vascular flow area (VFA) and blood flow velocity on carotid Doppler US. Results: In the final analysis, 49 patients were included and 3 groups of stenosis were obtained, comprising 21 subjects with no stenosis, 19 with mild stenosis and 9 with moderate stenosis. Right eye and left eye groups were formed. In the right eye group with right ICAS, we found statistically significant results for FAZ circularity when comparing the normal stenosis group to the mild stenosis group (p = 0.025) and the mild stenosis group to the moderate stenosis group (p = 0.006). Statistically significant results were also observed for NFA when comparing the normal stenosis group to the moderate stenosis group (p = 0.004) and the mild stenosis group to the moderate stenosis group (p = 0.011). When comparing the FAZ area (p = 0.016) and VFA (p = 0.037) for the normal and moderate groups, statistically significant values were obtained. When comparing the normal and moderate stenosis groups with regard to the left eye, we found statistically significant results for VFA (p = 0.041), NFA (p = 0.045) and VFA (p = 0.029). When comparing the mild and moderate carotid artery stenosis groups, we obtained statistically significant results for NFA (p = 0.001), FAZ area (p = 0.007) and VFA (p = 0.013). In the right eye group, correlations between internal carotid artery (ICA) peak systolic velocity (PSV) and VFA (rho = -0.286), ICA end-diastolic velocity (EDV) and NFA (r = 0.365), external carotid artery (ECA) PSV and VFA (r = -0.288; rho = -0.317), common carotid artery (CCA) PSV and NFA (rho = -0.345), CCA EDV and NFA (rho = -0.292) and VA PSV and VFA (r = -0.327; rho = -0.379) were found. When analyzing OCTA parameters, we found statistically significant results for NFA and VFA (r = -0.374; rho = -0.288). Correlations were also found in the left eye group between ICA PSV and NFA (r = -0.351; rho = -0.313), ICA EDV and VFA (r = -0.421; rho = -0.314), ECA PSV and NFA (r = -0.412; rho = -0.457), CCA PSV and NFA (p = -0.288; rho = -0.339), and CCA EDV and NFA (r = -0.404; rho = -0.417). Conclusions: Our study found correlations between carotid Doppler velocities and OCTA vascular flow parameters; thus, OCTA may be used as a tool for monitoring the microvascular changes associated with carotid stenosis. OCTA can provide insights concerning the overall vascular condition of the patient, since it provides subjective data on vessel density and flow; therefore, by monitoring hypertensive patients with both OCTA and carotid Doppler US, we may be able to increase efficiency in screening and diagnosing patients with IACS.